Mission control schedules our days into increments as short as five minutes using a program called OSTPV (Onboard Short Term Plan Viewer), which rules our lives. Throughout the day, a dotted red line moves relentlessly across the OSTPV window on my laptop, pushing through the block of time mission control has estimated for each task. NASA people are optimists by nature, and unfortunately this optimism can extend to the estimate of how long it will take me to perform a certain task, such as repairing a piece of hardware or conducting an experiment. If I take longer than scheduled to complete a task, the extra time has to come out of something else on the schedule—a meal, my exercise time, the brief time I get to myself at the end of the day (which OSTPV labels “pre-sleep”), or—worst of all—sleep. Most of us wind up having complicated relationships with the line on the OSTPV screen. Sometimes when I’m working on something challenging, the line seems to speed up malevolently, and I could swear something is wrong with it. Other times, it seems to settle down and match the passage of time as I perceive it. Of course, if I could somehow zoom out my view of the schedule wide enough to take in the entire year, the line would be creeping forward so slowly it wouldn’t appear to be moving at all. Today’s schedule seems well thought out, but there are a few ways in which things could go wrong. For Terry, Samantha, and me, much of today is to be taken up with one long task labeled DRAGON CAPTURE.
From the outside, the International Space Station looks like a number of giant empty soda cans attached to one another end to end. The length of the station is made up of five modules connected the long way—three American and two Russian. More modules, including ones from Europe and Japan as well as the United States, are connected as offshoots to port and starboard, and the Russians have three that are attached up and down (we call these directions zenith and nadir). Between my first mission to the space station and this one, it has grown by seven modules, a significant proportion of its volume. This growth is not haphazard but reflects an assembly sequence that had been planned since the beginning of the space station project in the 1990s. Whenever visiting vehicles are berthed here—resupply spacecraft like the Russian Progress, American Cygnus, Japanese HTV, or SpaceX Dragon—for a time there is a new “room,” usually on the Earth-facing side of the station; to get into one of them, I have to turn “down” rather than turning left or right. Those rooms get roomier as we get the cargo unpacked, then get smaller again as we fill them with trash. Not that we need the space—especially on the U.S. segment, the station feels quite roomy, and in fact we can lose one another in here easily. But the appearance of extra rooms—and then their disappearance, after we set them loose—is a bit strange. It used to be that uncrewed cargo vehicles were built as one-use spacecraft, and after we detached them from the station they burned up in the atmosphere. The relatively new SpaceX Dragon has the capability to return to Earth intact, which gives us more flexibility.
I won’t get to spend time outside the station until my first of two planned spacewalks, which won’t be for almost seven months. This is one of the things that some people find difficult to imagine about living on the space station—the fact that I can’t step outside when I feel like it. Putting on a spacesuit and leaving the station for a spacewalk is an hours-long process that requires the full attention of at least three people on station and dozens more on the ground. Spacewalks are the most dangerous thing we do on orbit.
Even if the station is on fire, even if it’s filling up with poisonous gas, even if a meteoroid has crashed through a module and our air is rushing out, the only way to escape the station is in a Soyuz capsule, which also needs preparation and planning to depart safely. We practice dealing with emergency scenarios regularly, and in many of these drills we race to prepare the Soyuz as quickly as we can. No one has ever had to use the Soyuz as a lifeboat, and no one hopes to.
The space station is an international effort and a shared facility, but in practice I spend almost all of my time on the cluster of modules—which, together with American and Japanese visiting vehicles—we call the U.S. operational segment. My cosmonaut colleagues spend the majority of their time on the Russian segment, consisting of the Russian modules as well as the visiting Russian Progress and Soyuz spacecraft.
The module where I spend a lot of my day is the U.S. module formally named Destiny, but which we mostly just call “the lab.” It’s a state-of-the-art scientific laboratory with walls, floors, and ceiling packed with equipment. Because there is no gravity, every surface is usable storage space. There are science experiments, computers, cables, cameras, tools, office supplies, freezers—crap all over the place. The lab looks cluttered—people with OCD would probably have trouble living and working here—but the things I use most I can put my hands on in seconds. There are also a large number of things I would not be able to put my hands on if asked—without gravity, items wander off regularly, and the ground will often email us WANTED posters regarding lost objects, like the ones the FBI puts in post offices. Occasionally one of us will dislodge a tool or part that has been missing for years. Eight years is the record, so far, for a missing object reappearing.